Problem in editing interface of android studio XML layout

Question

Build.Radle (app)

apply plugin: 'com.android.application'

android {
    compileSdkVersion 28
    defaultConfig {
        applicationId "com.example.karlo.menu"
        minSdkVersion 15
        targetSdkVersion 28
        versionCode 1
        versionName "1.0"
        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    implementation fileTree(dir: 'libs', include: ['*.jar'])
    implementation 'com.android.support:appcompat-v7:28.0.0-rc02'
    implementation 'com.android.support:design:28.0.0-rc02'
    implementation 'com.android.support.constraint:constraint-layout:1.1.3'
    implementation 'com.google.android.gms:play-services-ads:12.0.1'
    implementation 'com.google.android.gms:play-services-auth:12.0.1'
    implementation 'com.google.firebase:firebase-messaging:12.0.1'
    testImplementation 'junit:junit:4.12'
    androidTestImplementation 'com.android.support.test:runner:1.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    implementation 'com.google.firebase:firebase-core:16.0.1'
    implementation 'com.google.firebase:firebase-database:16.0.1'
    implementation 'com.google.firebase:firebase-crash:16.0.1'
    implementation 'com.google.firebase:firebase-auth:16.0.2'

}
apply plugin: 'com.google.gms.google-services'

Good afternoon. I’m not able to use the XML layout editor in android studio. This appears and I cannot drag the text fields or configure the distances and alignment. I find it much more intuitive to do using this editor than to edit the same code. Has anyone been there? Or could you help me solve the problem? Thanks in advance.